It's complicated, but essentially the game has deviated too far from its initial concept. You have a poor smithmaging system, uninspired crafting system, one-dimensional character building (majority of stats are sub-par, and while you can possibly make something viable, you'll still be second-best to more popular builds), new content virtually mirroring old content, unlike Dofus where certain areas at least have continuity and are connected, Wakfu is just a series of random islands. When these elements appear poorly made from the start and you have to re-do them three times, and they're worse than they were in the beginning, then this tells you something. Wakfu will never compare to Dofus in its prime. It was fun when it was first released because people saw it had potential, but that potential never realized and sadly never will. The game is too far gone now. As others have said, the people who play it enjoy for what it is, or have invested too much time and effort to quit.
I enjoyed it back when I played, but I doubt I'll ever play again. The spell-revamp broke the camel's back for me.
But hey, if you like it, play. I know it's a little discouraging playing a game that isn't very populated, but if you can find some enjoyment with the small crowd you have around you, don't let it deter you. I just had ulterior motives.